Lord of the Rings by J.R.R. Tolkien
Purely as a matter of convenience, we tend to be taught The Hobbit if anything Tolkien when it comes to school. Taking the time to go over at least Fellowship of the Ring, however, would present a lot more interesting stuff when it comes to the quality of craft. Tolkien was, on one hand, one of the best world-builders ever. On the other, he tended to pad his work with meaningless details pretty often, too. Creative writing classes could definitely do with a thorough examination of what works and what doesn’t about these fantasy classics.